Computer assisted biokinetic studies of radiopharmaceuticals in animals and humans. III. Dosimetry of /sup 99m/Tc-labelled microcolloids for lymphokinetic studies

A quantitative kinetic scintillation camera technique has been developed for investigation of the lymph drainage and the uptake in lymph nodes of /sup 99m/TcSb2S3 colloid injected subcutaneously. A model has been designed for calculating absorbed doses to injection site, lymph nodes, liver gonads and whole body based on these measurements. The kinetics of the colloid uptake in individual nodes could be expressed by a simple two-compartment model. The outflow of colloid from the injection site was monoexponential. The volume of the injected colloid at the injection site was quantitatively studied and shown to increase with time. The average absorbed doses were calculated either with the MIRD-formalism or with a computer program for calculations of absorbed doses. The most probable absorbed dose to the injection site was shown to be about 15,000 μGy/MBq